The present invention relates to the field of water treatment and, more particularly, to novel compositions for treating (e.g., disinfecting and conditioning) water in circulating reservoirs such as pools, spas, hot-tubs, whirlpool bathtubs and similar structures.
Water reservoirs which are used by humans for bathing, e.g., for sports, recreational, therapeutic, hygienic, decorative and/or ceremonial purposes, require standing by certain mandatory, regulatory, customary and fashionable criteria. These include health related criteria which deal mostly with controlling pathogens of biological sources and the chemical composition of the water. Health criteria ensure that the water is effectively free of microbes and harmful substances which are responsible for acute and chronic human illness, and is environmentally safe. Other criteria deal with elements of choice and aesthetics such as taste, color, turbidity, odor and pH.
Typical water treatments employ physical, chemical, and biological procedures, and any combinations thereof, which are aimed at providing the water with the required and desired qualities. Chemical treatment of water includes conventional use of chemicals such as oxidizing and non-oxidizing biocides, algaecides, sanitizers, disinfectants, pH and alkalinity adjusters, dispersants, surfactants, corrosion and fur (scale) control agents, fouling control agents and deodorizing, odorizing and colorizing agents. Physical treatment of water includes filtration, aeration, irradiation, sedimentation and subjection to electromagnetic fields. Biological treatment of water, which is less common with water reservoirs used for bathing, includes enzymatic treatment and maintenance of a desired ecologic balance by means of microflora and higher species. Still, the predominant method for water treatment is based on a combination of filtration and chemical treatment.
The chemical treatment is typically a part of an overall water maintenance, treatment, conditioning and purification program, in which the required chemicals are usually added independently. The water is monitored periodically, following several parameters of the water quality, and when a particular parameter deviates from the acceptable range, the appropriate amount of the necessary chemical is added. Usually, adjusting one water quality parameter influences another water quality parameter. Therefore, conventional chemical water treatment and conditioning requires continuous balancing procedures which include monitoring the water quality parameters and adjustment with appropriate dosing of various chemicals to create and maintain the required and desired water quality.
Without this treatment, bacteria and algae may flourish uncontrollably and rather quickly in the water, especially in circulating reservoirs, and more so in those which are kept at an elevated temperature, such as heated swimming pools which are kept at 24-27° C., and hot-tubs and spas which are kept at 38-40° C.
Usually water quality improvement via chemical treatments is achieved by treating the water with strong oxidizers and/or active-halogen containing sanitizers. “Active halogen” is a phrase which is used herein to describe Cl+ and Br+, also known and referred to in the art as “free halogens” or “available halogens”. Active halogens are known as highly effective antimicrobial agents, having a wide biocidal activity (e.g., antibacterial, antifungal, antialgal and antiviral activities), and thus are routinely used in water treatment systems.
Hypochlorous and hypobromous acids (HOCl and HOBr respectively) are common sources of active halogen and are frequently used as aggressive oxidizing and sanitizing agents for various applications, including water treatment systems. Hypochlorite and hypobromite ions are less effective sanitizers than the corresponding acids, therefore the pH of the water is maintained so as to favor a high concentration of the acid and a low concentration of the ions.
Other strong oxidizers that are typically used in water treatment include, for example, sodium- or potassium-persulfate, and sodium- or potassium-monopersulfate.
However, direct use of halogens and other strong oxidizers is limited as a result of the complications which arise from practical issues such as handling, storage, transport and disposal thereof, mainly due to their high reactivity and aggressiveness as oxidizing agents. Therefore, the use of compounds that are capable of releasing or generating active chlorine and/or bromine upon contact with water, and thus act as indirect oxidizing agents, is preferred. Moreover, hypochlorous and hypobromous acids are highly reactive and hence the concentration thereof diminishes rapidly due to consumption during reactions with the organic compounds and matter introduced to the water by bathers. Furthermore, hypochlorous and hypobromous acids deplete and readily decomposes into inactive breakdown products, such as hydrochloric acid or hydrobromic acid, water and oxygen, via UV radiation driven photochemical reactions upon exposure to direct sun light, and/or upon exposure to moderate and high temperatures, and thus require constant replenishment and the use of chemical stabilizers in order to control these effects and preserve the effectiveness of these sanitizers. The need for constant addition of sanitizers and stabilization thereof is greater still when the water of the circulating reservoir is kept at an elevated temperature, such as in hot-tubs and whirlpool bathtubs which are kept at 38-40° C., wherein the processes by which the chemicals are degraded and evaporate is hastened.
Hence, chemical compounds, such as trichloroisocyanuric acid (TCCA), sodium dichloroisocyanurate, 1-bromo-3-chloro-5,5-dimethylhydantoin, 1-chloro-3-bromo-5,5-dimethylhydantoin, 1-bromo-3-chloro-5-methyl-5-ethylhydantoin, 1-chloro-3-bromo-5-methyl-5-ethylhydantoin, 1-bromo-3-chloro-5,5-diethylhydantoin, 1-chloro-3-bromo-5,5-diethylhydantoin, 1-bromo-3-chloro-5-ethyl-5-methylhydantoin, 1-chloro-3-bromo-5-ethyl-5-methylhydantoin, 1,3-dichloro-5-ethyl-5-methylhydantoin, 1,3-dibromo-5-ethyl-5-methylhydantoin, 1,3-dichloro-5-methyl-5-ethylhydantoin, 1,3-dibromo-5-methyl-5-ethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin, 1,3-dichloro-5,5-diethylhydantoin, 1,3-dibromo-5,5-diethylhydantoin, any combination thereof and various, more rapidly dissolving salts thereof, are the major and most commonly used sanitizers in circulating reservoirs. These compounds combine the release of active halogen disinfectant agents together with the protective action thereof, when coming in contact with water, and ensure that the water remains clean and safe for the bathers (see, for example, release and stabilization of hypochlorous and hypobromous acids by 3-bromo-1-chloro-5,5-dimethylhydantoin in Scheme 1 below).

However, these active-halogen generating sanitizers, and especially the products of their interactions with protein-based residues and various organic amines present in water, add unpleasant odors to the water and hence to the surrounding of the reservoir containing the water. These malodorous substances have an intensified impact in heated water of spas and hot-tubs due to their volatility.
Other than guarding the quality of water, and thus guarding the users of a circulating reservoir against microorganisms, active-halogen generating sanitizers, which addition thereof is considered compulsory, do not have any other beneficial effect, such as soothing, nurturing and/or healing qualities, on the well-being of the bathers. These highly desired qualities have been sought by humans for centuries.
In order to achieve such qualities, other chemical additives are optionally added to circulating reservoirs. Such chemical additives are aimed at improving the life quality of the bathers and in some cases treat health issues such as skin ailments, inflammation, pain, general physical infirmity and other physiological conditions as well as stress, fatigue, exhaustion and other mental conditions.
Bathing therapies have been known as early as the times of ancient Egypt and the Roman empire, where wealthy families availed themselves of “scented and anointed waters” to allegedly alleviate a virtual panoply of diseases, from minor muscular discomfort to life-threatening disease. This activity, which also provided the scene for social interactions, took place in natural hot springs and mineral springs as well as in man-made reservoirs. In modern times, many people of common standing can avail themselves with such pleasures or needs in public or privately owned circulating reservoirs, such as hot-tubs, whirlpool bathtubs and spas, without the need to travel to remote and scarce locations.
The most commonly and traditionally used additives for water in circulating reservoirs, which allow simulating the conditions found in natural hot and mineral springs, are bath salts. Bath salts are known as useful for relaxation, medicinal therapy and aromatherapy for many years. Modern bath therapies involve the use of commercially available salts, such as those found in sea salt and epsom salt, primarily comprised of various ion pairs of sodium, magnesium, potassium, calcium, chloride, bromide and sulfate.
Commercially available bath salts include, for example, Carnallite, which is an evaporite mineral comprising hydrated potassium magnesium chloride (KMgCl3.6(H2O), other Dead-Sea salt products typically comprising water (about 36.4%), magnesium chloride (about 33.3%), potassium chloride (about 24.3%), sodium chloride (about 5.5%), bromide (about 0.5%), calcium chloride (about 0.2%), sulfates (about 0.15%) and insolubles (about 0.03%), and other sea and oceanic salts optionally formulated along with other minerals.
Bath salts are typically hygroscopic at ambient temperatures and hence handling, packaging, storage and usage thereof are inconvenient and require special conditions and treatment, which influences their commercial utility. For example, Carnallite, as well as other bath salts which are based on Carnallite, are so hygroscopic, that their intense tendency to adsorb water from the surrounding air will transform a solid, dry sample into a concentrated solution if left in contact with the ambient atmosphere. Camallite-based products are therefore packed in tightly sealed packages until used.
Commercially available bath salts are typically upgraded by the addition of odoriferous substances, which bestow a pleasant feeling to those using the water reservoir. Modern and traditional odoriferous substances include essential aromatic oils and other natural and modified extracts from plants and animals, as well as synthetic fragrances and perfumes. Odoriferous substances which can be used in bathing water are taught in, for example, U.S. Pat. Nos. 3,963,648, 4,051,076, 4,917,891 and 6,426,325. Other suitable essential oils and aromatic substances, such as wintergreen oil, clove oil, nutmeg oil, anise oil, vanilla oil, thyme oil, mint oil, sassafras oil, rose oil, orange oil, pine oil, rosewood oil, eucalyptus oil, ylang-ylang oil, lavender oil, patchouli oil and musk oil, are of traditional and folkloric origins and are readily available.
However, while most odoriferous substances are considered benign and even beneficial for use as additives in circulating reservoirs which are used for human bathing, blending of odoriferous substances with strong oxidizing agents, such as those generating active halogens, may result in a baneful oxidation of the odoriferous substances; leading to diminishing beneficial effects. In order to reduce the likelihood for this incompatibility, great care is practiced in the choice of stable odoriferous substances, and careful planning of their storage, formulation and addition thereof.
Other compatibility and safety issues become crucial when dealing with the use and storage of different water treatment chemicals, some of which are toxic, aggressive and highly reactive upon exposure to air, moisture and one with another. For example, oxidizers and other chemicals that are added to circulating reservoirs are often not compatible when blended with each other and hence the activity of the oxidizer or sanitizer can rapidly diminish as a result of such a mingle. Furthermore, while some water treatment chemicals are required to reach a final desired concentration rapidly and adjacently upon commencement of use of the water such as “pool-shock” products (aimed at rapid oxidative breakdown of water-soluble bather waste) and bath salts, other chemicals, such as halogen-releasing compounds and volatile odoriferous substances, are infused slowly and throughout the time period of use. Therefore, treating and maintaining the water of a circulating reservoir is characterized by a delicate balance of demand, stability, compatibility and solubility. Difference in solubility alone may undermine the objectives of the water treatment plan if not considered and addressed.
It becomes evident that an overwhelmingly large number of chemicals force the average owner/proprietor/operator of a circulating reservoir, even a relatively small one, to spend considerable time and resources to maintain a wide spectrum of chemicals and to determine when, how much and for what purpose each of these chemicals must be added to the water system. In addition, substantial understanding of chemistry is required so as to avoid hazards, damages and inefficiency, as a result of an inadequate chemical treatment.
However wishful, an “all-in-one” multifunctional product for general reservoir maintenance that would prevent flawed used while still providing all the desired functions and benefits of water treatment is chemically and practically difficult to achieve in view of the limitations discussed hereinabove and thus is not yet available to consumers. Nevertheless, a product with even a partial multifunctionality would have great value in easing the task of maintaining water that requires such chemical treatment and conditioning.
Some non-obvious formulations and multifunctional products for water treatment are known, and include, for example, sanitizing, cleansing and refreshing products for use in toilet bowls, dishwashers, swimming pools, spas and other home and industrial water applications.
For example, while bath salts and odoriferous substances are often sold and used separately, thus adding to the already large number of water-maintenance chemicals mentioned above, some compositions such as those taught in, for example, U.S. Pat. No. 5,958,462, combine bath salts and essential oils into one product.
Other multifunctional products containing combined water treatment chemicals, especially those which include an oxidizer/sanitizer component, may actually be based on the differences in solubility of various chemicals so as to address the differences in the demanded administration thereof. Products which are based on compacting various water treatment chemicals having dissimilar solubility in different layers are disclosed in, for example, U.S. Pat. Nos. 3,873,685 and 6,863,830, which teach the combination of several layers in one tablet wherein one layer contains a fast dissolving halogen-releasing agent while a second layer provides a slower dissolving halogen-releasing agent. Various geometric shapes of tablets are suggested in these patents, wherein the discrete portions of the ingredients are provided in structures having either a layered structure or an inner core and outer core such as in the shape of a rod or oval ball. These products deliver sanitizers and stabilizers; however they fail to provide other highly sought qualities and benefits as discussed hereinabove, such as those obtained from chemicals such as odoriferous substances and bath salts.
Yet other multifunctional products, such as those taught in U.S. Pat. No. 6,852,238, are aimed at a safe and effective combination of two incompatible chemicals: a halogen source and a pH compensating source, in the form of a multi-layered tablet. The water treatment composition described in this patent comprises a multi-layer tablet wherein one discrete layer contains at least one halogen source and a second discrete layer contains at least a pH compensating source. Still these products fail to provide other highly sought qualities and benefits.
In an attempt to avoid oxidation of an odoriferous substance by a sanitizing substance as mentioned hereinabove, U.S. Pat. No. 5,759,974 and EP 1553162 disclose lavatory cleansing and freshening blocks, having a layer or a core comprising one substance and a layer or a shell comprising the other substance. While these disclosures teach the combination of two chemically and physically incompatible substances, they fail to teach water treatment products which are suitable for human bathing, and which include other chemicals such as bath salts.
U.S. Pat. No. 6,617,297 discloses automatic dishwashing tablets with improved chlorine stability, stemming from the use of certain nonionic surfactants in machine dishwashing detergent tablets containing chlorinating agents. This disclosure also fails to teach formulations which are suitable for human bathing.
U.S. Pat. No. 5,256,328 discloses a liquid toilet bowl cleaning and sanitizing composition comprising an aqueous dispersion of particles of at least one halogen donating compound. Other than teaching a liquid composition, which is unsuitable for the chemicals which are used in water treatment of circulating reservoirs, this disclosure also fails to teach formulations which are suitable for human bathing.
Other multifunctional products of various detergents and sanitizers are taught in, for example, U.S. Pat. Nos. 4,731,195 and 6,174,192, yet, these patents are not directed at products for circulating water reservoirs designed for human bathing as mentioned above, and hence none addresses the issues of combining reactive sanitizers, with beneficial substances such as the hygroscopic bath salts and/or the volatile and oxidation prone odoriferous substances.
There is thus a widely recognized need for, and it would be highly advantageous to have multifunctional formulations, which can conveniently provide a combination of desired chemicals to water of circulating reservoirs.